MEMS wavelength converting lighting device and associated methods

ABSTRACT

A lighting device is described for receiving source light within a predetermined source wavelength range, converting the source light into a converted light, and reflecting the converted light to a desired output direction. The lighting device may use a micro electromechanical system (MEMS) device to receive and redirect the source light to the desired output direction. A conversion coating may be applied to the operative surface of the MEMS device to convert the source light into a converted light.

FIELD OF THE INVENTION

The present invention relates to the field of lighting devices and, morespecifically, to applying a conversion coating to a repositionablesurface of a MEMS lighting device to direct a light of variablewavelength ranges in a desired output direction.

BACKGROUND OF THE INVENTION

Lighting devices that include a conversion coating conveniently allowthe conversion of light from a source light source into a light of adifferent wavelength range. Often, such conversion coatings are createdby using a phosphorous coating. These wavelength conversion coatings maysometimes applied to lenses located in line with the light projectedfrom a light source. In some instances the conversion coating may beapplied to the light source itself. A number of disclosed inventionsexist that describe lighting devices that utilize a conversion coatingto convert light with a source wavelength range into light convertedwavelength range.

Color-mixing, tunable white lighting devices are traditionallycontrolled via PWM (pulse width modulation). PWM is a common techniquefor controlling power to electrical devices, which operates by quicklyswitching power between an “on” state and “off” state during eachperiod. The period is the time between each pulse, similar to a clockrate. The ratio of the pulse period occupying the “on” state versus the“off” state defines the duty cycle. As the PWM varies the duration thatthe switch is kept at the “on” state, the PWM is able to vary theaverage power to the load device. PWM switching can be beneficial froman efficiency perspective, since it has low power loss when the switchesare in the “off” state.

For lighting devices, the frequency of pulses in the PWM circuit must besufficiently fast enough such that the human eye cannot perceive thestrobe effect. To have an increasingly high pulse frequency, the periodmust become increasingly short. The intensity of each individual colormay be controlled via variations in the duty cycle of each pulse period.With light sources that are slow to react, such as incandescent lightbulbs, a relatively low pulse frequency may be required. Conversely, PWMcircuits that may be used to control a perceived intensity of lightemitting semiconductors must be operable at considerably higherfrequencies, or otherwise risk producing visual flicker.

To achieve color mixing, a PWM circuit should generally be able tocontrol the duty cycle on all colors intended to be mixed. Typically,any color can be created through the use of a red, green, and blue colorsource. With a color mixing system based on PWM circuits, the system mayadjust the duty cycle for each primary color by combining the adjustedprimary colors to display the desired color. The primary colors arenormally combined via a lens.

Micro-electro-mechanical systems (MEMS) use a configuration differentfrom PWM to control the intensity of light. In MEMS, the light from eachlight source is preferably directed to an array of microscopic mirrors,which reflect the light in different directions. Typically, a MEMS “on”state includes reflecting the light into a lens, wherein the light maybe combined with light of other colors. Traditionally, multiple lightsources are combined in MEMS to create a desired output color,including, for example, a red source, a green source, and a blue source.

U.S. Published Patent Application No. 2010/0046234 to Abu-Ageeldiscloses the use of wavelength conversion layers which includedifferent types or amounts of phosphor. The Abu-Ageel '234 applicationgives an example of a wavelength conversion layer that may include ablend of red, green, and blue phosphors. These phosphors are excited bythe light source and emit a light at a different wavelength range. Thered, green and blue light generated by the conversion layers is thencombined to form a white light. The Abu-Ageel '234 application alsodiscloses the use of a blue light source, wherein the direct blue lightis combined with a phosphor converted red and green light to create awhite light. Furthermore, the Abu-Ageel '234 application specificallycites the use of micro-electro-mechanical systems (MEMS) and opticallenses which are Used to focus a beam of light emitted by a source. Adeflector can be used to scan a light beam between two or more types ofwavelength conversion materials.

U.S. Published Patent Application No. 2010/0321641 to Van Der Lubbediscloses utilizing a one-colored light source, and converting fractionsof that light into other colors. The Van Der Lubbe '641 application alsodiscloses using phosphors arranged in a first and second set of pixelsfor a color converting optical element.

U.S. Pat. No. 7,832,878 to Brukilacchio et al., discloses phosphors orother wavelength converting elements that can be employed over an LEDdie to result in wavelengths and spectral bandwidths not readilyavailable from a standard LED die. The Brukilacchio et al. '878 patentadditionally discloses the use of a digital micromirror device (DMD)projection system in combination with a rotating color wheel.

U.S. Published Patent Application No. 2010/0302464 to Raring et al.discloses the use of a phosphor coating on an optical member to create alaser beam of a desired color by using a phosphor material to alter thelight generated by LEDs and/or laser diodes. These colored laser beamsmay then be emitted to a DMD from an optical member.

There exists a need for a lighting device that provides an ability toreceive a light emitted from a light source in one wavelength range andredirect the light in a desired output direction in another wavelengthrange. There further exists a need for a lighting device that combinesconversion and redirection of the light emitted from a light source inone operation.

SUMMARY OF THE INVENTION

With the foregoing in mind, the invention is related to a lightingdevice that may advantageously receive a source light emitted from alight source in one wavelength range and redirect the light to a desiredoutput direction in another wavelength range. The lighting device canalso advantageously combine conversion and redirection of the sourcelight in one operation. By providing one lighting device thatadvantageously combines these operations, the present invention maybeneficially possess characteristics of reduced complexity, size, andmanufacturing expense.

These and other objects, features, and advantages according to thepresenting invention are provided by a lighting device for directingsource light within a predetermined source wavelength range in a desiredoutput direction that may include a MEMS device and a conversioncoating. The MEMS device may include at least one operative surface toreceive and redirect the source light towards the desired outputdirection. The conversion coating may include a phosphorous wavelengthcoating material, which may be applied to at least one operative surfaceto convert the source light into a converted light within at least oneconverted wavelength range. In embodiments of the present invention, theMEMS device may be a digital micromirror device (DMD). The DMD mayinclude an array of mirrors that may be positionable between multipleangles to reflect the converted light. The predetermined sourcewavelength ranges may include a plurality of wavelength ranges, whereineach of the plurality of wavelength ranges may be selectively enabled.

The lighting device of the present invention may receive a source lightthat is a monochromatic light, bichromatic light, or polychromaticlight. The source light may have a wavelength range within at least oneof a blue spectrum and an ultraviolet spectrum. Source light in theultraviolet spectrum may have a predetermined source wavelength rangebetween 200 nanometers and 400 nanometers. Source light in the bluespectrum may have a predetermined source wavelength range between 400nanometers and 500 nanometers.

A lighting device of the present invention may include a positiondetecting device. The desired output direction may include a projectionsurface. The position detecting device may sense a location of theprojection surface to define a location of a sensed projection surface.The position detecting device may further include a repositioning devicethat repositions the MEMS device to project the converted light to thelocation of the sensed projection surface.

A method aspect of the present invention is for using the lightingdevice. The method may include the steps of receiving a source light,converting the source light into a converted light, and reflecting theconverted light to a desired output direction. The converted light mayinclude light within a predetermined wavelength range.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial side elevation view of a lighting device accordingto the present invention illustrating a MEMS device receiving andreflecting light.

FIG. 1A is a partial side elevation view of an embodiment of thelighting device illustrated in FIG. 1 showing a MEMS device receivingand reflecting light from a plurality of light sources.

FIG. 2 is a perspective view of a MEMS device of a lighting deviceaccording to the present invention.

FIG. 2A is a schematic block diagram of the MEMS device illustrated inFIG. 2.

FIG. 3 is a partial front elevation view of a MEMS package of a lightingdevice according to the present invention.

FIG. 4 is a front elevation view of a MEMS cell of a lighting deviceaccording to the present invention.

FIG. 5 is top plan view of the MEMS package of FIG. 3.

FIGS. 6A and 6B are top plan views of embodiments of the MEMS packageillustrated in FIG. 5.

FIG. 7 is a partial side elevation view of a position detecting device,repositioning device, and projection surface of the lighting deviceaccording to the present invention.

FIGS. 7A, 7B, and 7C are partial side elevation views of the lightingdevice illustrated in FIG. 7 reflecting converted light on variousprojection surfaces.

FIG. 8 is a flowchart detailing transmission, conversion, and reflectionof light in accordance a method aspect of the present invention.

FIG. 9 is a flowchart detailing operation of controlling a desiredoutput direction of converted light in accordance with a method aspectof the present invention.

FIG. 10 is a partial side elevation view of the MEMS package illustratedin FIG. 3.

FIG. 11 is a flowchart detailing transmission, conversion, andreflection of light using the MEMS package illustrated in FIG. 10.

FIG. 12 is a partial side elevation view of the MEMS package illustratedin FIG. 3.

FIG. 13 is a flowchart detailing transmission, conversion, andreflection of light using the MEMS package illustrated in FIG. 12.

FIG. 14 is a flowchart detailing operation of a position detectingdevice according to a method aspect of the present invention.

FIG. 15 is a flowchart detailing operation of the MEMS device to reflectlight in a desired output direction in response to a position signalaccording to a method aspect of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention will now be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the invention are shown. This invention may, however, be embodied inmany different forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Those ofordinary skill in the art realize that the following descriptions of theembodiments of the present invention are illustrative and are notintended to be limiting in any way. Other embodiments of the presentinvention will readily suggest themselves to such skilled persons havingthe benefit of this disclosure. Like numbers refer to like elementsthroughout.

In this detailed description of the present invention, a person skilledin the art should note that directional terms, such as “above,” “below,”“upper,” “lower,” and other like terms are used for the convenience ofthe reader in reference to the drawings. Also, a person skilled in theart should notice this description may contain other terminology toconvey position, orientation, and direction without departing from theprinciples of the present invention.

Referring now to FIGS. 1-15, a lighting device 10 according to thepresent invention in now described in greater detail. Throughout thisdisclosure, the lighting device 10 may also be referred to as a systemor the invention. Alternate references of the lighting device 10 in thisdisclosure are not meant to be limiting in any way.

As perhaps best illustrated in FIG. 1, the lighting device 10 accordingto an embodiment of the present invention includes a device that uses amicroelectromechanical system, or MEMS device 20, a source light 42, anda converted light 46. The converted light 46 may be directed by the MEMSdevice 20 in a desired output direction 60. A conversion coating 30 maybe applied to the MEMS device 20 to convert the source light 42 into theconverted light 46, as will be described in greater detail below, and asperhaps best illustrated in FIGS. 3, 4, 6A, 6B, 10, and 12.

As illustrated, for example, in FIG. 1, the MEMS device 20 may receivethe source light 42. This source light 42 may originate from a lightsource 40. In embodiments of the present invention, the light source 40may include light emitting diodes (LEDs) capable of emitting light in apredetermined source wavelength range. Other embodiments of the presentinvention may include source light 42 that is generated by a laserdriven light source. Those skilled in the art will appreciate that thesource light 42 may be provided by any number of lighting devices. Thesource wavelength range may include a source light 42 emitted in blue orultraviolet wavelength ranges. However, a person of skill in the art,after having the benefit of this disclosure, will appreciate that LEDscapable of emitting light in any wavelength ranges may be used in thelight source 40, in accordance with this disclosure of the presentinvention. A skilled artisan will also appreciate, after having thebenefit of this disclosure, additional light generating devices that maybe used in the light source 40 that are capable of creating anillumination.

As previously discussed, embodiments of the present invention mayinclude a light source 40 that generates source light 42 with a sourcewavelength range in the blue spectrum. The blue spectrum may includelight with a wavelength range between 400 and 500 nanometers. A sourcelight 42 in the blue spectrum may be generated by a light emittingsemiconductor that is comprised of materials that may emit a light inthe blue spectrum. Examples of such light emitting semiconductormaterials may include, but are not intended to be limited to, zincselenide (ZnSe) or indium gallium nitride (InGaN). These semiconductormaterials may be grown or formed on substrates, which may be comprisedof materials such as sapphire, silicon carbide (SiC), or silicon (Si). Aperson of skill in the art will appreciate that, although the precedingsemiconductor materials have been disclosed herein, any semiconductordevice capable of emitting a light in the blue spectrum is intended tobe included within the scope of the present invention.

Additionally, as previously discussed, embodiments of the presentinvention may include a light source 40 that generates source light 42with a source wavelength range in the ultraviolet spectrum. Theultraviolet spectrum may include light with a wavelength range between200 and 400 nanometers. A source light 42 in the ultraviolet spectrummay be generated by a light emitting semiconductor that is comprised ofmaterials that may emit a light in the ultraviolet spectrum. Examples ofsuch light emitting semiconductor materials may include, but are notintended to be limited to, diamond (C), boron nitride (BN), aluminumnitride (AlN), aluminum gallium nitride (AlGaN), or aluminum galliumindium nitride (AlGaInN). These semiconductor materials may be grown orformed on substrates, which may be comprised of materials such assapphire, silicon carbide (SiC), or Silicon (Si). A person of skill inthe art will appreciate that, although the preceding semiconductormaterials have been disclosed herein, any semiconductor device capableof emitting a light in the ultraviolet spectrum is intended to beincluded within the scope of the present invention.

The light source 40 of the present invention may include an organiclight emitting diode (OLED). An OLED may be a comprised of an organiccompound that may emit light when an electric current is applied. Theorganic compound may be positioned between two electrodes. Typically, atleast one of the electrodes may be transparent.

The light source 40 may produce a source light 42 with an organicwavelength range, or wavelength range that triggers psychological cueswithin the human brain. These organic wavelength ranges may include oneor more wavelength ranges that trigger positive psychological responses.The positive psychological responses may be similar to those realized inresponse to natural light or sunlight.

A person of skill in the art will appreciate that the lighting device 10may receive a source light 42 that is monochromatic, bichromatic, orpolychromatic. A monochromatic light is a light that may include onewavelength range. As perhaps best illustrated in FIG. 1A, a bichromaticlight is a light that includes two wavelength ranges, which may bederived from one or two light sources 40. A polychromatic light is alight that may include a plurality of wavelength ranges, which may bederived from one or more light sources 40.

Referring now additionally to FIG. 2, additional features of thelighting device 10 of the present invention will now be discussed ingreater detail. More specifically, the MEMS device 20 will now bediscussed. A MEMS device 20 is formally known as amicroelectromechanical system device. This name reflects the nature ofMEMS devices 20, since many microscopic mechanical components areincluded as part of a total system. The mechanical components may beorganized into MEMS cells 22, wherein an array of MEMS cells 22 may beincluded in the MEMS package 21. As perhaps best illustrated in theblock diagram of FIG. 2A, the MEMS package 21, along with amicrocontroller 28, and other additional components, may collectivelycomprise the MEMS device 20.

The components of a MEMS device 20 are mechanical because the MEMSdevice 20 may be comprised of a plurality of movable parts. Thesemovable parts, which collectively form the components, may include arepositionable surface 34 and positioning components 24, which will bediscussed in greater detail below, and which are perhaps be bestillustrated in FIG. 4. The positioning components 24 may be used tomanipulate the repositionable surface 34. The components thatcollectively form a MEMS cell 22 will be discussed in greater detailbelow.

The components are microscopic because the movable parts may be verysmall, and may only be measurable on a micrometer scale. The componentsmay also be part of a system. Due to a miniaturization of components ofthe MEMS device 20, the components may be densely located in a smallarea. Several microscopic components may be operatively connected toform a MEMS cell 22. As a result, a plurality of microscopic componentsoperatively connected in a small area may be configured as a pluralityof MEMS cells 22. Dense collections of MEMS cells 22 may be packagedtogether, such as, for example, on a semiconductor, in a MEMS package21. A person of skill in the art will appreciate that some MEMSconfigurations, such as with larger MEMS configurations, may be packagedon multiple semiconductors, which may be interconnected and mayintercommunicate as a system.

Referring now to FIGS. 2 and 2A, the MEMS device 20, and morespecifically the MEMS package 21, of the light device 10 will now bediscussed greater detail. A MEMS package 21 may be included in largerelectronic systems or located on a dedicated integrated circuit (IC)chip. In some embodiments of the present invention, the components ofthe IC may collectively form a MEMS device 20. In the foregoingdescription, for illustrative purposes that are not intended to belimiting, this disclosure of the present invention assumes that the MEMSpackage 21 is located on an IC. A person of skill in the art, afterhaving the benefit of this disclosure, however, will appreciate thenumerous applications for integrating a MEMS package 21, in addition tothose mentioned herein, that may or may not include an IC. As a result,a skilled artisan should not interpret the description of a MEMS package21 as being integrated into an IC as limiting.

In addition to the MEMS package 21, the MEMS device 20 may additionallyinclude a microcontroller 28 and IC contacts 29, which may be includedin an IC body 27. The microcontroller 28 may receive one or more inputsignals via the IC contacts 29. The input signal may include informationregarding the desired operation of the mechanical parts of the MEMSdevice 20. The microcontroller 28 may then process the informationreceived in the input signal to determine control signals that mayoperate each MEMS cell 22 of the MEMS device 20. The control signals maybe used to control the position of the mechanical components of eachMEMS cell 22. Through the selective positioning of the mechanicalcomponents of individual MEMS cells 22, the lighting device 10 of thepresent invention may advantageously control the characteristics of theconverted light 46 by reflecting light with the desired convertedwavelength range in the desired output direction 60.

Referring now additionally to FIGS. 3-5, additional features of thelighting device 10 of the present invention are now discussed in greaterdetail. More specifically, the MEMS package 21 of the lighting device 10will be discussed herein. A MEMS device 20 may include at least one MEMScell 22, organized in an array on a MEMS package 21 (FIG. 3). The arrayof MEMS cells 22 may be located on a packaging semiconductor 23 (FIG.5), thus creating the MEMS package 21.

Referring now additionally to FIG. 4, additional features of thelighting device 10 of the present invention are now discussed in greaterdetail. More specifically, the structural configuration of the MEMS cell22, a plurality of which may be configured to create the MEMS package21, will now be discussed. The MEMS cell 22 may include a MEMS cell base26, positioning components 24, and a repositionable surface 34. Therepositionable surface 34 may also be referred to as an operativesurface throughout this disclosure and the accompanying claims. Therepositionable surface 34 may include a reflective surface that mayreflect light. In an embodiment of the present invention, therepositionable surface 34 may be a micromirror. However, a person ofskill in the art will appreciate, after having the benefit of thisdisclosure, that any surface capable of accepting a source light 42 andredirecting that light in a desired output direction 60 would beincluded within the scope and spirit of the present invention.

The MEMS cell base 26 may be comprised of a semiconductor material fromwhich the other components of the MEMS cell 22 are formed. Thesemiconductor material may include silicon, but a person of skill in theart will appreciate additional semiconductor materials that will beincluded within the scope and spirit of the present invention. Due toflexibility properties inherent to silicon, when on the microscopicscale, the mechanical components of a MEMS device 20 formed from siliconmay be repositioned with minimal energy dissipation. Silicon alsoprovides the benefit of minimal fatigue characteristics realized duringmechanical operation. This minimal fatigue characteristic mayadvantageously provide trillions of mechanical operations before failuremay occur. A person of skill in the art will appreciate additionalmaterials that may be used to form the MEMS cell base 26, such as butnot limited to, polymers and metals.

The MEMS cell base 26 may also include electronic components thatcontrol the operation of the mechanical components of the MEMS cell 22.The electronic components may include an electronic connection to themicrocontroller 28. Through this connection, the MEMS cell 22 mayreceive operational instructions from the microcontroller 28 via aconfiguration signal. The electronic components of the MEMS cell base 26may also include a SRAM bank, which may be used to apply an electricalcharge to the mechanical components through bias voltages, which mayfurther allow the repositionable surface 34 to be selectivelypositioned. The use of bias voltage to control the MEMS cells 22 mayallow the lighting device 10 to advantageously manipulate the lightreflected in the desired output direction 60 from each MEMS cell 22 inan array, such as a MEMS package 21, simultaneously. The use of a biasvoltage may additionally allow the MEMS device 20 to operate under a lowvoltage requirement, beneficially providing efficient operation.

The positioning components 24 may be formed from the MEMS cell base 26through the processes of creating a plurality of material layers,patterning the layers with photolithography, etching the patternedlayers into the shapes of the mechanical components of the MEMS cell 22,and depositing the layers together. Each of the layers deposited withinthe creation of the mechanical components of each MEMS cell 22 may be ofa thickness on the scale of micrometers to nanometers.

The positioning components 24 may be formed to provide the mechanicalmotion of the repositionable surface 34. In the preferred embodiment,the positioning components 24 may be configured to allow motion abouttwo axes. However, a person of skill in the art will appreciatealternate embodiments that may provide pivotal motion about one or moreaxes.

The positioning components 24 of the MEMS cell 22 may include mechanicalcomponents of at least one support structure, a yoke structure, and apair of electrodes to control the operation of the other mechanicalstructures and the position of the repositionable surface 34. As anelectrical current is applied to the electrodes of the positioningcomponents 24, an electrostatic force may cause the mechanical structureof additional positioning components 24 to be physically repositioned.This repositioning may be a rotation about an axis on which a mechanicalpositioning component is located. Upon receiving an electric current,the electrostatic force may cause the mechanical positioning componentto be reoriented by a distance that may be measured on a scale ofpicometers. However, due to micrometer scale of each MEMS cell 22, andthe components included therein, this degree of reorientation maybeneficially provide an adequate range of motion necessary to allow therepositionable surface 34 a significant degree of mobility.

By providing a range of motion for the repositionable surface 34, thepositioning components 24 may allow the MEMS cell 22 to reflect sourcelight 42 in a desired output direction 60. This may be accomplished bymodifying the angles at which the repositionable surface 34 has beenrotated about one or more axes. This rotation may be provided by thepositioning components 24. As the repositionable surface 34 isreoriented by the positioning components 24, the angle of reflection,which defines the direction of reflected light, may be altered.

This alteration to the angle of reflection may advantageously allow theMEMS cell 22 to redirect the source light 42 in a desired outputdirection 60. This desired output direction 60 may be determined by oneor more control signals received by the microcontroller 28 of the MEMSdevice 20, which may control one or more MEMS cells 22.

In some embodiments of the lighting device 10 of the present invention,the MEMS device 20 may be a digital micromirror device, or DMD. A DMD isa type of MEMS device 20 that may include a plurality of micromirrors,or microscopic mirrors, arranged in a rectangular array. Due to themicroscopic size of the micromirrors, a DMD may include several hundredthousand micromirrors, or more, in a single device. A person of skill inthe art will appreciate that although a rectangular array has beendepicted in the appended figures, a DMD device of the present inventionmay include micromirrors configured in an array of any shape and stillremain functional to reflect a source light 42 in a desired outputdirection 60. As a result, such alternately configured arrays should beconsidered to be included within the scope and spirit of the presentinvention.

Although the following paragraphs describe the structure of the MEMSdevice 20 as a DMD, a person of skill in the art will appreciate thestructural descriptions for the DMD may be applied to a MEMS device 20.In the following paragraphs, the micromirror of the DMD may be thestructural equivalent of the repositionable surface 34 of the MEMSdevice 20. The micromirror may simply be an embodiment of therepositionable surface 34 wherein the surface is reflective. As such,skilled artisans should additionally regard the following paragraphs asa disclosure for MEMS based lighting devices 10 in general, and notrestrict the disclosure solely to DMD devices.

The micromirrors of the DMD may be constructed of a reflective material,such as, but not limited to, aluminum. Each micromirror may becontrolled by the positioning components 24 of the DMD. Considering thatthe DMD is a type of MEMS device 20, the DMD may share the structuralconfiguration of the previously described MEMS device. Preferably, themicromirrors included in the DMD may be capable of being rotatedapproximately 12 degrees in either direction about an axis. A person ofskill in the art will appreciate, after having the benefit of thisdisclosure, that a micromirror included in the DMD may be rotated moreor less than 12 degrees and remain within the scope and spirit of thepresent invention.

This rotation of each micromirror may allow the respective micromirrorto transition between an “on” state and an “off” state. The “on” stateof a micromirror may be initiated when the micromirror is positioned toreflect light in the desired output direction 60. The “off” state of amicromirror may be initiated when the micromirror is positioned toreflect light in a direction other than the desired output direction 60.In embodiments, in the “off” state, the reflected light may be directedat a light absorbing member. An example of a light absorbing member mayinclude, but should not be limited to, a heatsink.

Each of the micromirrors of the DMD array may correspond with a pixel ofthe light being outputted by the DMD. These pixels may be combined tocreate an image that may be displayed on a projection surface 62. Theprojection surface 62 will be discussed in further detail below. Throughthe manipulation of each micromirror, the image may be continuallyupdated to display a desired color pattern or image in the desiredoutput direction 60. Through the rapid positioning of each micromirrorin the “on” or “off” states, the DMD may reflect or project an animatedpicture or video image in the desired output direction 60.

Throughout the remainder of this disclosure, the present invention willbe discussed as a MEMS configuration, generally. A skilled artisan willappreciate that the structural configuration of a MEMS configuration isintended to include the structural configuration of a DMD, since the DMDis an application of MEMS technology. The MEMS cells 22 may be organizedin a grid configuration, such as illustrated by FIG. 5. Various gridconfigurations may be used, which may include the non-limiting exampleof a square grid presented in FIG. 5. However, a person of skill in theart will appreciate that the MEMS cells 22 may be organized in anyconfiguration on the MEMS package 21 that may allow the reflection ofsource light 42 in a desired output direction 60.

For clarity, the MEMS package 21 of FIG. 5 is presented as a version ofa MEMS package 21, which may be included as part of the preferredembodiment of the MEMS device 20 of the present invention. In thepreferred embodiment, an array of MEMS cells 22 may include any numberof MEMS cells 22, and not necessarily the number of MEMS cells depictedin FIG. 5. Due to the microscopic nature of MEMS devices 20, the MEMSdevice may include MEMS cells 22 with measurements as small as 1micrometer by 1 micrometer. A person of skill in the art will appreciatethat, although the disclosure provided herein contemplates a MEMS device20 with a plurality of MEMS cells 22, the present invention may includea MEMS device 20 with as little as one MEMS cell 22, and still beincluded within the scope and spirit of the present invention.

The repositionable surface 34 of the MEMS device 20 may include aconversion coating 30 applied to alter the source wavelength range ofthe source light 42 into a converted wavelength range of the convertedlight 46, which is perhaps best illustrated in FIG. 4. The conversioncoating 30 is preferably provided by a phosphorous coating capable ofconverting a light with a source wavelength range into a light with oneor more converted wavelength ranges. However, it will be appreciated byskilled artisans that any coating that may be capable of converting alight from one wavelength range to another wavelength range may beapplied to the repositionable surface 34 and be included within thescope and spirit of the present invention.

A conversion coating 30, such as a coating based on a phosphorousmaterial, may alter the wavelength range of light that may betransmitted through the coating. A source wavelength range may beconverted into at least one converted wavelength range. As discussedabove, a source light 42 may include a monochromatic, bichromatic, orpolychromatic light emitted by one or more light sources 40. For thesake of clarity, references to a source light 42, and its correspondingsource wavelength range, should be understood to include the lightemitted by the one or more light sources 40 received by the MEMS device20 of the lighting system 10. Correspondingly, a source wavelength rangeshould be understood to be inclusive of the wavelength ranges includedin monochromatic, bichromatic, and polychromatic source lights 42.

Additionally, a source light 42 with a source wavelength range may beconverted by the conversion coating 30 into a converted light 46 withmultiple converted wavelength ranges. The use of multiple phosphorelements may produce a light that includes multiple discrete oroverlapping wavelength ranges. These wavelength ranges may be combinedto produce the converted light 46. For further clarity in the foregoingdescription, references to a converted light 46, and its correspondingconverted wavelength ranges, should be understood to include allwavelength ranges that may have been produced as the source light 42 maypass through the conversion coating 30.

A phosphor substance may be illuminated when it is energized. Energizingof the phosphor may occur upon exposure to light, such as the sourcelight 42 emitted from the light source 40. The wavelength of lightemitted by a phosphor may be dependent on the materials from which thephosphor is comprised.

In an embodiment of the lighting device according to the presentinvention, a plurality of conversion coatings 30 may be applied to therepositionable surfaces 34 of each MEMS cell 22. For example, aplurality of phosphors may be used that are capable of generating green,blue, and red converted light 46. When these conversion coatings 30 areapplied to the repositionable surface 34 of the MEMS cell 22, therepositionable surface 34 may reflect light in the converted wavelengthrange of the corresponding conversion coating 30. For clarity,repositionable surfaces 34 coated with a green, blue, and red conversioncoating 30 may be referred to in this disclosure, respectively, as agreen repositionable surface 34G, blue repositionable surface 34B, andred repositionable surface 34R. This configuration of colored MEMS cells22 in a MEMS package 21 may perhaps be best illustrated in FIGS. 6A and10.

Referring now to FIG. 6A and FIG. 10, the conversion coatedrepositionable surfaces 34G, 34B, and 34R (illustrated in FIG. 10) maybe evenly distributed. This even distribution may result in the uniformreflection of converted light 46, since the green repositionable surface34G, blue repositionable surface 34B, and red repositionable surface 34Rmay occupy approximately the same proportional area of the packagingsemiconductor 23. A person of skill in the art will appreciate that anon-uniform distribution of the proportional area occupied by the greenrepositionable surface 34G, blue repositionable surface 34B, and redrepositionable surface 34R are to be included in this disclosure, assuch configuration may be demanded by the desired application of thelighting device 10.

A person of skill in the art, after having the benefit of thisdisclosure, will appreciate that conversion coatings 30 that producelight in a wavelength range other than green, blue, and red may beapplied to the repositionable surfaces 34 of the MEMS cells 22 andtherefore be included within the scope and spirit of the presentinvention. A skill artisan will additionally realize that any number ofconversion coatings 30, which may be capable of producing convertedlight 46 of various converted wavelength ranges and correspondingcolors, may be applied to the repositionable surfaces 34 of the MEMScells 22 and still be included within the scope of this disclosure.

The preceding example, depicting three discrete color conversioncoatings 30, is not intended to be limiting in any way. Instead, thedescription for the preceding example has been provided for illustrativepurposes, solely as a non-limiting example. A skilled artisan willappreciate that any wavelength range, and therefore any correspondingcolor, may be produced by a conversion coating 30 applied to arepositionable surface 30 and remain within the scope of the presentinvention. Thus, the lighting device 10 of the present invention shouldnot in any way be limited by the preceding example.

As perhaps best illustrated in FIG. 6B, an additional embodiment of theMEMS device 20 of the lighting device 10 according to the presentinvention may receive a blue source light 42. More specifically, a MEMSdevice 20 may include a plurality of MEMS cells 22, wherein a number ofMEMS cells 22 may not have a conversion coating 30 applied to itsrepositionable surface 34. The lack of an application of a conversioncoating 30 may allow the respective repositionable surface 34 to reflectthe source light 42 as it is received by the MEMS cell 22. Additionaldesired colors may be provided by applying a conversion coating 30 tothe repositionable surfaces 34 of the remaining corresponding MEMS cells22.

A non-limiting example of the embodiment of the preceding paragraph ispresented below, wherein the source light 42 is within a blue wavelengthrange. Since the source light 42 is already emitted in a blue wavelengthrange, no conversion may be required to reflect a blue light in thedesired output direction 60. Conversely, since the source light 42 isemitted as a blue light, a conversion coating 30 may be applied to therepositionable surfaces 34G and 34R of a proportional number of MEMScells 22G and 22R to convert the source light 42 into a converted light46 with the desired converted wavelength range. Referring to the exampledepicted in FIG. 6B, areas of green repositionable surfaces 34G, redrepositionable surfaces 34R, and repositionable surfaces 34 with noapplication of a conversion coating 30 may be distributed to occupyapproximately the same proportional area. As a blue source light 42 isreceived by the MEMS device 20, the MEMS device 20 may thus reflect aconverted light 46 that include a light in the green wavelength range,blue wavelength range, and red wavelength range.

A person of skill in the art will appreciate, after having the benefitof this disclosure, that a source light 42 with any source wavelengthrange may be received by the MEMS device 20 and converted into aconverted wavelength range. The embodiment illustrated by FIG. 6B mayalso receive a source light 42 in the red wavelength range and includeareas of green repositionable surfaces 34G, blue repositionable surfaces34B, and repositionable surfaces 34 with no application of a conversioncoating 30.

Referring now to FIG. 7, additional features of the lighting device 10according to an embodiment of the present invention are now described ingreater detail. More specifically, the desire output direction 60 of theconverted light 46 will now be discussed. After a source light 42 hasbeen converted by the MEMS device 20 into a converted light 46, it maybe reflected in a desired output direction 60. The lighting device 10 ofthe present invention may reflect the converted light 46 generally inthe desired output direction 60 wherein the reflected light may diffuseinto a volume, such as a room or stage. The converted light 46 reflectedby the lighting device 10 may thus illuminate the volume.

Alternately, the converted light 46 may be reflected such that thedesired output direction 60 may include a projection surface 62. In someembodiments, the projection surface 62 may be an area spatially locatedin the desired output direction 60, such as, but not to be limited to, awall or screen. In other embodiments, the projection surface 62 may bean object intended to receive the converted light reflected by the MEMSdevice.

Since the lighting device 10 of the present invention may include a MEMSdevice 20 with conversion coatings 30 applied directly to therepositionable surfaces 34 of each MEMS cell 22, the lighting device 10of the present invention may advantageously project a dynamic image onan irregular projection surface 62 using a minimal number of movableparts. The operation of the lighting device 10 of the present inventionwill be discussed in greater detail below.

A projection surface 62 may include any surface of an object on whichlight may be projected. In addition to defining a projection surface 62as a wall or screen, as described above, the projection surface 62 mayinclude objects that do not have rectangular or regular shape. Asperhaps best illustrated in FIG. 7A, the projection surface 62 may alsoinclude a sculpture, or other non rectangular object. As illustrated inthe example provided in FIG. 7A, wherein a spherical structure isillustrated, the converted light 46 may be reflected by the MEMS device20 on the spherical projection surface 62.

A projection surface 62 may additionally include any surface of anon-stationary object, or an object that may that may reposition itselfor be repositioned, as perhaps best described in the examplesillustrated in FIGS. 7B and 7C. In the example illustrated in FIG. 7B,the projection surface 62 may be a person. The projection surface 62 mayalso be an object with random movement characteristics, such as thewater fountain that is depicted for exemplary purposes in FIG. 7C. Thelighting device 10 may be able to track the movement of a person, waterfountain, or other projection surface 62 via a position detecting device64. A person of skill in the art will appreciate that the previousexamples of a sculpture, person, and water fountain have been providedonly as examples, and are not intended to be limiting in any way. Askilled artisan will also appreciate that any object, whether stationaryor moving, may be used as a projection surface 62 within the scope ofthe present invention.

A position detecting device 64 may be used to determine the spatiallocation of the projection surface 62. Embodiments of the positiondetecting device 64 may use one or more configurations of positionsensing components to determine the location of the projection surface62. A person of skill in the art will appreciate that a positiondetecting device 64 may be configured to control one or more MEMS device20.

Examples of possible position sensing configurations will now bediscussed. The position detecting device 64 may use at least one camerato determine the location of the projection surface 62. Two or morecameras may be used to determine the distance between the projectionsurface 62 and the lighting device 10 of the present invention. In anembodiment of the present invention, the cameras of the positiondetecting device 64 may be positioned at equivalent distance apart fromeach other, which may allow the position detecting device 64 todetermine depth. The position detecting device 64 may then determine thedistance between the projection surface 62 and the position detectingdevice 64 by calculating a depth algorithm.

The position detecting device 64 may use alternate or additionalposition detecting configurations. These position detectingconfigurations may include, but should not be limited to, radar, sonar,infrared, RFID, laser targeting, and other position detecting mechanismsthat should be apparent to a person of skill in the art.

Once the position detecting device 64 has determined the location of theprojection surface 62, it may create a position output denoting thelocation of the projection surface 62. The position output may bereceived by any device capable of interpreting the signal includedtherein, such as the MEMS device 20 and/or a repositioning device 66.

If the position output is received by the MEMS device 20, the MEMSdevice 20 may control the MEMS cells 22 included therein to reflect theconverted light 46 in a desired output direction 60 that correspondswith the detected location of the projection surface 62. As theprojection surface 62 may reposition itself or be moved, the positiondetecting device 64 may detect the new position of the projectionsurface 62. The position detecting device 64 may then output a newposition signal, which may be received by the MEMS device 20. As aresult, the MEMS device 20 may reorient the desired output direction 60of the converted light 46 to correspond to the present location of theprojection surface 62. This operation may occur continually.

Referring back to the water fountain example, as illustrated in FIG. 7C,the projection surface 62 may include a plurality of smaller surfaces.In the present example, these smaller surfaces may include streams 71and droplets 72 generated by the fountain. Furthermore, this pluralityof smaller surfaces may be scattered about a given area, spatiallyexisting at various positions and depths from each other.

After locating each smaller surface, which may collectively comprise theprojection surface 62, the MEMS device 20 may adapt the desired outputdirection 60 to reflect the converted light 46 to approximately the sameareas occupied by the smaller surfaces of the projection surface 62. Amore detailed example of this operation will be provided below.

Referring now to FIGS. 7, 7A, 7B, and 7C, the position detecting device64 may transmit the position signal to a repositioning device 66. Therepositioning device 66 may be operatively connected to the MEMS device20 to provide physical reorientation of the MEMS device 20. Thisphysical reorientation may advantageously allow the MEMS device 20 toreflect converted light 46 to an extended area that would otherwise beoutside of the range of a stationary MEMS device 20.

The repositioning device 66 may include motorized components capable ofrepositioning the MEMS device 20 in relation to a received input. Thereceived input may be a position input received by the positiondetecting device 64. Upon receiving the input, the repositioning device66 may control at least one motorized component to rotate the physicalposition of the MEMS device 20. A person of skill in the art willappreciate that although this disclosure discusses the use of motorizedcomponents to physically adjust or alter the orientation of the MEMSdevice 20, alternate repositioning structures may be used. Suchstructures may include, but should not be limited to, electromagneticsystems, pneumatics, hydraulics, and other position manipulating systemsthat would be appreciated by a person of skill in the art.

In another embodiment, the repositioning device 66 may manipulate alight redirecting structure other than the MEMS device 20. Thisstructure may be a mirror, configured to receive and redirect theconverted light 46 reflected by the MEMS device 20 via a secondreflection. The light directing structure may also be a lens, configuredto redirect the light that may pass through it. Yet another example of alight directing structure may be a waveguide. A skilled artisan willappreciate additional equivalent light redirecting structures that maybe controlled by a repositioning device 66, which may alter the path ofthe light reflected by the MEMS device 20, that are intended be includedwithin the scope and spirit of the present invention. The positiondetecting device 64 and the repositioning device 66 may be integratedinto one structure. Alternately, the position detecting device 64,repositioning device 66, and MEMS device 20 may all be integrated intoone structure.

In operation, the lighting device 10 of the present invention mayadvantageously convert and redirect the wavelength range of a sourcelight 42 in one operation. More specifically, the lighting device 10 ofthe present invention may receive a source light 42, convert the sourcewavelength range of the source light 42 into a converted wavelengthrange of a converted light 46, and reflect the converted light 46 in adesired output direction 60. A projection surface 62 may be included inthe desired output direction 60. The spatial position of the projectionsurface 62 may be detected by a position detecting device 64, from whicha repositioning device 66 may reorient a MEMS device 20 to allow thedesired output direction 60 to correspond with the location of theprojection surface 62.

The source light 42 may be generated by one or more light sources 40.The light source 40 may include at least one light generating element,as previously discussed, which may include LEDs, lasers, and/or otherlight emitting semiconductors. A skilled artisan will appreciate thatalthough the light source 40 is described as using a light emittingsemiconductor, any light generating structure may be used and remainwithin the scope and spirit of the present invention.

An LED may emit light when an electrical current is passed through thediode in the forward bias. The LED may be driven by the electrons of thepassing electrical current to provide an electroluminescence, oremission of light. The color of the emitted light may be determined bythe materials used in the construction of the light emittingsemiconductor. The foregoing description contemplates the use ofsemiconductors that may emit a light in the blue or ultravioletwavelength range. However, a person of skill in the art will appreciatethat light may be emitted by light emitting semiconductors of anywavelength range and remain within the breadth of the invention asdisclosed herein. Effectively, a light emitting semiconductor may emit asource light 42 in any wavelength range, since the emitted source light42 may be subsequently converted by a conversion coating 30 applied torepositionable surface 34 of the MEMS cells 22 as it is reflected in thedesired output direction 60.

Referring now additionally to flowchart 80 illustrated in FIG. 8, thetransmission, conversion, and reflection of light resulting from theoperation of the lighting device 10 of the present invention will now bediscussed in greater detail. Starting at Block 80S, the light source 40may emit a source light 42 (Block 81). The emitted source light 42 maythen be directed to the MEMS device 20, resulting in the source light 42being received by the MEMS device 20 (Block 82). Next, the source light42 may pass though the conversion coating 30 applied to therepositionable surface 34 of the MEMS cell 22 (Block 83). As the sourcelight 42 passes through the conversion coating 30, the source light 42may undergo a first wavelength conversion into an interim light (Block84).

The interim light may then be reflected by the repositionable surface 34of the MEMS cell 22 in the desired output direction 60 (Block 85). Aspreviously discussed, the repositionable surface 34 may be a micromirroror other reflective, repositionable surface 34. After being reflected,the interim light may again pass through the conversion coating 30applied to the repositionable surface 34 of the MEMS cell (Block 86).

The light may pass through the conversion coating 30 twice because theconversion coating 30 may be applied to the surface of therepositionable surface 34. By passing through the conversion coating 30twice, the lighting device 10 of the present invention mayadvantageously require the application of less conversion coating 30materials to the repositionable surface 34 of the MEMS cell 22. Thisbeneficially reduces the additional mass that may be repositioned by themechanical components of the MEMS cell 22, providing increasedreliability and efficiency.

As the interim light passes through the conversion coating 30, the lightmay undergo a subsequent wavelength conversion into a converted light 46(Block 87). The converted light 46 may then continue to travel in thedesired output direction 60, to which it may have been reflected by theMEMS device 20 (Block 88). The operation may then terminate (Block 80E).

Referring now additionally to the flowchart 90 illustrated in FIG. 9,the operation of controlling the desired output direction 60 of theconverted light 46 will now be discussed in greater detail. Theoperation starts at Block 90S, wherein a control program is interpretedby the microcontroller 28 of the MEMS device 20 (Block 92). The controlprogram may include a predetermined set of instructions included in amemory or data storage device. Alternately, the control program may beresponsive to a set of user inputs, dynamically controlling thewavelength range of the converted light 46 in response to a user input.A person of skill in the art, after having the benefit of thisdisclosure, will appreciate equivalent schemes by which themicrocontroller 28 may interpret a control program and operate the MEMScells 22 of the MEMS device 20.

Once the microcontroller 28 has interpreted the instructions of thecontrol program, the microcontroller 28 may transmit a control signal tothe MEMS cells 22 (Block 94). The MEMS cell 22 may then accept thecontrol signal and reposition its repositionable surface 34 accordingly(Block 96). The MEMS cell 22 may position the repositionable surface 34to have an intended angle of reflection. Once the repositionable surface34 has been properly positioned, light received by the MEMS cell 22 maybe reflected in the desired output direction 60 (Block 98). Theoperation may then terminate (Block 90E).

Referring now additionally to FIGS. 10 and 11, the operation ofreflecting the converted light 46 in the desired output direction 60 inaccordance with an embodiment of the present invention, will now bediscussed in greater detail. More specifically, an embodiment whereinthe source light 42 may be converted into a converted light 46 that mayinclude various converted wavelength ranges will now be discussed.

FIG. 10 illustrates an array of MEMS cells 22 grouped in a MEMS package21. For clarity, only three MEMS cells 22 have been illustrated therein,but a person of skill in the art will appreciate that any number of MEMScells 22 may be included in the MEMS package 21. Similarly, FIG. 10illustrates an array of MEMS cells 22 that may emit a converted light 46in varying converted wavelength ranges. These MEMS cells 22 may includea green MEMS cell 22G, blue MEMS cell 22B, and red MEMS cell 22R. TheseMEMS cells 22′ may respectively emit a converted light 46 that includesthree different wavelength ranges, a green converted light 46G, a blueconverted light 46B, and a red converted light 46R. These wavelengthranges of converted light 46 may be collectively reflected as oneconverted light 46, with a converted wavelength range, as previouslydiscussed. A person of skill in the art will appreciate that, throughthe application of conversion coatings 30 with the appropriatewavelength converting materials, such as phosphors, a converted light 46may be created with virtually any converted wavelength range. As such,the example provided herein is not intended to be limited in any way,and particularly not limited to the green converted light 46G, blueconverted light 46B, and red converted light 46R described herein.

Referring now to the flowchart 110 illustrated in FIG. 11, the operationof the MEMS device 20 of the present embodiment, which may reflect aconverted light 46 with varying converted wavelength ranges, is nowdescribed in greater detail. Starting at Block 110S, the control programmay be interpreted by the microcontroller 28 to determine the desiredconverted wavelength range (Block 112).

The MEMS device 20 may include a green MEMS cell 22G, a blue MEMS cell22B, and a red MEMS cell 22R. The microcontroller 28 may determine theamount of converted light 46 that may be reflected in the desired outputdirection 60 for each converted wavelength range by directing aproportion of the correspondingly colored MEMS cells 22 to reflect theconverted light 46 in the desired output direction 60. Alternately, themicrocontroller 28 may control the duty cycles of the MEMS cells 22 toalter the amount of light actually emitted in the desired outputdirection 60. Duty cycle control may be selectively applied to MEMScells 22 of a corresponding wavelength range or color to alter theamount of light actually reflected in the desired output direction 60for each wavelength range or color. In embodiments of the lightingdevice 10 of the present invention where the microcontroller 28 maycontrol the duty cycles of the color MEMS cells 22, such as the greenMEMS cells 22G, blue MEMS cells 22B, and red MEMS cells 22R, themicrocontroller 28 may control all MEMS cells 22 of a similar color withone control signal. Alternately, the microcontroller 28 may control theMEMS cells 22 individually, regardless of the wavelength conversioncoating 30 applied to the repositionable surface 34 thereof. A person ofskill in the art, after having the benefit of this disclosure, willappreciate equivalent control configuration that are within the scopeand spirit of the present invention.

The microcontroller 28 may control the intensity of each wavelengthrange or color by positioning a corresponding portion of the MEMS cells22 in the desired output direction 60. To control the MEMS cells 22, themicrocontroller 28 may send a control signal to the corresponding MEMScells 22, which may include the green MEMS cell 22G (Block 114G), blueMEMS cell 22B (Block 114B), and red MEMS cell 22R (Block 114R). Therespective MEMS cells 22 may then accept the control signal and positionits respective repositionable surface 34 accordingly (Blocks 116G, 116B,and 116R). Once the respective MEMS cells 22G, 22B, and 22R have beenpositioned accordingly, the light may be reflected in the desired outputdirection 60, comprising the desired output wavelength range (Block118). Thereafter, the operation may terminate (Block 110E).

Referring now additionally to FIGS. 12 and 13, the operation ofreflecting the converted light 46 in the desired output direction 60, inaccordance with an additional embodiment of the present invention, willnow be discussed in greater detail. More specifically, an embodimentwherein the source light 42 may be converted into pixels of convertedlight 46 including various converted wavelength ranges will be discussedherein.

FIG. 12 illustrates an array of MEMS cells 22 grouped in a MEMS package21. For clarity, only a limited number MEMS cells 22 have beenillustrated therein, but a person of skill in the art will appreciatethat a plurality of MEMS cells 22 may be included in the MEMS package21. Similarly, FIG. 12, viewed in light of FIG. 10, illustrates an arrayof MEMS cells 22 that may emit a converted light 46 in varying convertedwavelength ranges. These MEMS cells 22 may include a plethora ofindividually controlled pixel MEMS cells 22. These pixel MEMS cells 22may include, but should not be limited to, green MEMS cells 22G, blueMEMS cells 22B, and red MEMS cells 22R. These MEMS cells 22 mayrespectively reflect a converted light 46 that may include variouswavelength ranges, such as a green converted light 46G, a blue convertedlight 46B, and a red converted light 46R.

These wavelength ranges of converted light 46 may be individuallyreflected by each MEMS cell 22, forming an array of pixels, in responseto the control signal received by the microcontroller 28 of the MEMSdevice 20. Collectively, the pixels may be reflected as one convertedlight 46, with a converted wavelength range, as previously discussed.Alternately, the pixels may be selectively reflected such to produce aprojected static or animated image.

A person of skill in the art will appreciate that, through theapplication of conversion coatings 30 with the appropriate wavelengthconverting materials, such as phosphors, pixels may be created with aconverted light 46 of virtually any converted wavelength range. As such,the example provided herein is not intended to be limited in any way,and particularly not limited to the green converted light 46G, blueconverted light 46B, and red converted light 46R, or pixels formedtherefrom, as described herein.

Referring now to the flowchart 130 illustrated in FIG. 13, the operationof the MEMS device 20 of the present embodiment, which may reflect aconverted light 46 with varying converted wavelength ranges, is nowdescribed in greater detail. Starting at Block 130S, the control programmay be interpreted by the microcontroller 28 to determine the desiredconverted wavelength range (Block 132). In accordance with the presentlydescribed embodiment, the converted wavelength range may include anarray of wavelength converted pixels.

The MEMS device 20 may include a plurality of pixels. These pixels maybe formed by green MEMS cells 22G, blue MEMS cells 22B, and red MEMScells 22R. A person of skill in the art will appreciate that anyconversion coating 30 may be applied to the repositionable surface 34 ofthe MEMS cells 22, to create a pixel of converted light 46 with aconverted wavelength range, and remain within the scope and spirit ofthe present invention.

The microcontroller 28 may determine the number of pixels of convertedlight 46 that may be reflected in the desired output direction 60 foreach converted wavelength range. The microcontroller may then instruct aproportion of the correspondingly colored MEMS cells 22 to reflect theconverted light 46 in the desired output direction 60. Alternately, themicrocontroller 28 may control the duty cycles of the MEMS cells 22 of acorresponding wavelength range or color to alter the amount of lightactually emitted by each pixel in the desired output direction 60. Inembodiments of the lighting device 10 according to the presentinvention, where the microcontroller 28 may control the duty cycles ofthe color MEMS cells 22, such as green MEMS cells 22G, blue MEMS cells22B, and red MEMS cells 22R, the microcontroller 28 may control the MEMScells 22 collectively or individually. If controlled individually, thestate of the individual pixels may be controlled to create a static oranimated image, which may be reflected in the desired output direction60. A person of skill in the art, after having the benefit of thisdisclosure, will appreciate equivalent control configuration that arewithin the scope and spirit of the present invention.

The microcontroller 28 may control the intensity of each pixel bypositioning a corresponding MEMS cell 22 to reflect its converted light46 in the desired output direction 60. To control the MEMS cells 22, themicrocontroller 28 may send a control signal to the MEMS cells 22 thatcorrespond with a desired pixel (Blocks 134 p 1, 134 p 2, . . . , 134p(n−1), and 134 p(n)). Although the control of only four pixels has beenrepresented in FIG. 13, a person of skill in the art will appreciatethat a plurality of pixels may be controlled by the microcontroller 28of the MEMS device 20. The respective MEMS cells 22 may then accept thecontrol signal and position the repositionable surface 34 associatedtherewith accordingly (Blocks 136 p 1, 136 p 2, . . . , 136 p(n−1), and136 p(n)). Once the respective MEMS cells 22 have been positionedaccordingly, the converted light 46 may be reflected in the desiredoutput direction 60 comprising the desired output wavelength range orimage (Block 138). Thereafter, the operation may terminate (Block 130E).

Referring now additionally to FIG. 14, the operation of the detectingthe spatial position of a projection surface 62, in accordance with anadditional embodiment of the present invention, will now be discussed ingreater detail. The operation described in flowchart 140 may begin atBlock 140S. The position detecting device 64 may identify a projectionsurface 62 (Block 142). The position detecting device 64 may use one ormore configuration of position sensing components to determine thelocation of the projection surface 62.

As previously discussed along with the structural description of theposition detecting device 64, and as additionally illustrated in FIGS.7, 7A, 7B, and 7C, the position detecting device 64 may use cameras todetermine the location of a projection surface 62. If two or morecameras are used, the position detecting device 64 may determine thedistance between the projection surface 62 and the lighting device 10 byperforming a depth algorithm. The position detecting device 64 may alsouse other position detecting configurations, such as, but not limitedto, radar, sonar, infrared, RFID, laser targeting, and other positiondetecting mechanisms that should be apparent to a person of skill in theart.

The position detecting device 64 may include a computer program capableof performing a position calculating algorithm. This algorithm may beused to determine the spatial location of the projection surface 62(Block 144). In an embodiment of the position detecting device 64 of thelighting device 10 according to the present invention, an array ofcamera sensors may analyze a series of captured images. These capturedimages may be captured and analyzed at a high frequency. However, aperson of skill in the art will appreciate that images may be capturedat any frequency and remain consistent with the scope and spirit of thepresent invention.

The position detecting device 64 may detect the changes in location ofan object, such as the projection surface 62, reported by each camerasensor. The position detecting device 64 may then apply theaforementioned algorithms that may compare the captured images.Algorithms may be used to determine a delta distance that the projectionsurface 62 has moved between each image captured by each camera sensor.The algorithms may additionally use the delta distance, as reported byeach camera sensor, to triangulate the three-dimensional location of theprojection surface 62. A person of skill in the art will appreciateadditional position detecting mechanisms capable of locating aprojection surface 62, as intended to be included within the scope ofthe present invention.

Once the position detecting device 64 has determined the location of theprojection surface 62, it may create a position signal output denotingthat location. The position detecting device 64 may then transmit theposition signal data to any device capable of interpreting the signalincluded therein, such as the MEMS device 20 or a repositioning device66 (Block 146). The operation may then determine whether a shutdowncommand has been received (Block 148). If no shutdown command has beenreceived, the position detecting device 64 may again perform theoperation of Block 142, wherein it may identify the projection surface62. If a shutdown command has been detected at Block 148, the operationwill terminate (Block 140E).

Referring now additionally to FIG. 15, the operation of directing thedesired output direction 60 of the MEMS device 20, in accordance with anembodiment of the present invention, will now be discussed in greaterdetail. The operation described in flowchart 150 may begin at Block150S, wherein the device controlling the desired output direction 60 mayreceive the position signal from the position detecting device 64 (Block152). The position signal may be received by a MEMS device 20, arepositioning device 66, or another device configured to receive aposition signal.

If the position signal is received by the MEMS device 20, the MEMSdevice 20 may adjust the desired output direction 60 of the MEMS device20 accordingly (Block 154). Alternately, if the position signal isreceived by a repositioning device 66, the repositioning device 66 mayadjust the orientation of the MEMS device 20, or light reflectedtherefrom, accordingly (Block 155). The position signal may also bereceived by both the MEMS device 20 and the repositioning device 66,wherein both the MEMS device 20 and repositioning device 66 wouldperform the respective operation as described in Blocks 154 and 155. Aperson of skill in the art will appreciate that additional devicescapable of receiving a position signal may receive the position signaland perform the corresponding action as directed from the positionsignal.

Through the repositioning operation performed by the repositioningdevice 66 and/or MEMS device 20, the MEMS device 20 may then reflect theconverted light 46 in the desired output direction 60, which may beapproximately equal to the spatial location of the projection surface 62(Block 156). The operation may then determine whether a shutdown commandhas been received (Block 158). If no shutdown command has been received,the operation will return Block 152, wherein it may again receive aposition signal. If a shutdown command has been detected at Block 158,the operation will terminate (Block 150E).

If the position output is received by the MEMS device 20, the MEMSdevice 20 may control the MEMS cells 22 included therein to reflect theconverted light 46 to a desired output direction 60 that correspondswith the detected location of the projection surface 62. As theprojection surface 62 may reposition itself or move, the MEMS device 20may continually reorient the desired output direction 60 of theconverted light 46 to correspond to the present location of theprojection surface 62. As illustrated in FIG. 7C, the projection surface62 may include a plurality of smaller surfaces. Furthermore, theplurality of smaller surfaces may be scattered about a given area,spatially existing at differing positions and depths from each other.

After locating the smaller surfaces, which may collectively comprise theprojection surface 62, the MEMS device 20 may adapt the desired outputdirection 60 to reflect the converted light 46 to approximately the sameareas occupied by the smaller surfaces of the projection surface 62.

The following examples are included solely for illustrative purposes,with the intent to assist a person of skill in the art to betterunderstand the present invention as disclosed herein. The followingexamples are in no way intended to limit the uses or applications of thepresent invention. Additionally, the following examples are not intendedlimit the operation of the lighting device 10 of the present inventionto the embodiments listed below. A person of skill in the art willappreciate, after having the benefit of this disclosure, that the scopeof the invention disclosed herein is intended to include a multitude ofequivalent designs and configurations.

Referring to the previously mentioned example of a projection surface 62as being a person, as illustrated in FIG. 7B, the position detectingdevice 64 may detect a specified article of the persons clothes that isdesired to receive the converted light 46. For this example, a jacket 69may be considered to be the projection surface 62. The positiondetecting device 64 may detect the jacket 69, as it may be repositionedin response to the movements of the person wearing it. The positiondetecting device 64 may then transmit the position signal to the MEMSdevice 20, allowing the MEMS device 20 to control the desired outputdirection 60 to reflect the converted light 46 in only the spatialposition currently occupied by the jacket 69. As a result of outputtingthe converted light 46 in a desired output direction 60 that correspondswith the jacket 69 (projection surface 62), the surface may appear tohave a dynamically changing color or pattern.

In another example, referring to the previously mentioned water fountainexample illustrated in FIG. 7C, the position detecting device 64 maydetect the streams 71 and corresponding droplets 72 of water (smallersurfaces), which collectively create the fountain spray (projectionsurface 62) outputted by the fountain. The position detecting device 64may detect the streams 71 and droplets 72 of the fountain spray andgenerate a position signal. The position signal may then be transmittedto the MEMS device 20. The MEMS device 20 may then control the desiredoutput direction 60 to reflect the converted light 46 in only thespatial positions currently occupied by a stream 71 or correspondingdroplet 72.

As a result of outputting the converted light 46 in a desired outputdirection 60 that corresponds with the smaller surfaces, whichcollectively create the projection surface 62, the water outputted bythe fountain may appear to be illuminated by the light projectedthereon. Also, through the selective control of the MEMS cells 22 of theMEMS device 20, the wavelength ranges, and therefore the color, of theconverted light 46 may be altered as desired. This may create theadvantageous effect of a dynamically colored fountain without the needfor static or inefficient under-lighting from a flood light.

Many modifications and other embodiments of the invention will come tothe mind of one skilled in the art having the benefit of the teachingspresented in the foregoing descriptions and the associated drawings.Therefore, it is understood that the invention is not to be limited tothe specific embodiments disclosed, and that modifications andembodiments are intended to be included within the scope of the appendedclaims.

1. A lighting device for directing source light within a predeterminedsource wavelength range in a desired output direction, the lightingdevice comprising: a micro electromechanical system (MEMS) device thatincludes at least one operative surface to receive and redirect thesource light towards the desired output direction; a conversion coating,that includes a phosphorous wavelength coating material, applied to theat least one operative surface to convert the source light into aconverted light within a predetermined at least one converted wavelengthrange; wherein the MEMS device is a digital micromirror device (DMD)that includes an array of mirrors positionable between multiple anglesto reflect the converted light; and wherein the predetermined sourcewavelength ranges includes a plurality of wavelength ranges that areselectively enabled.
 2. A lighting device according to claim 1 whereinthe source light is a monochromatic light.
 3. A lighting deviceaccording to claim 1 wherein the source light is a bichromatic light. 4.A lighting device according to claim 1 wherein the source light is apolychromatic light.
 5. A lighting device according to claim 1 whereinthe predetermined source wavelength range is within at least one of ablue spectrum and an ultraviolet spectrum.
 6. A lighting deviceaccording to claim 5 wherein the predetermined source wavelength rangeof the source light within the ultraviolet spectrum is between 200nanometers and 400 nanometers.
 7. A lighting device according to claim 5wherein the predetermined source wavelength range of the source lightwithin the blue spectrum is between 400 nanometers and 500 nanometers.8. A lighting device according to claim 1 further comprising a positiondetecting device; and wherein the desired output direction includes aprojection surface.
 9. A lighting device according to claim 8 whereinthe position detecting device senses a location of the projectionsurface to define a location of a sensed projection surface.
 10. Alighting device according to claim 9 further comprising a repositioningdevice that repositions the MEMS device to project the converted lightto the location of the sensed projection surface.
 11. A lighting deviceaccording to claim 1 further comprising at least one light source thatgenerates the source light in the predetermined source wavelength range.